Rep. Greg Gianforte (R-Mont.) is tied with his Democratic challenger in Montana’s at-large congressional race, according to a poll from Gravis Marketing. The new poll shows Gianforte, who won a special election last year, in a dead heat with former Democratic state Rep. Kathleen Williams, with both candidates having the support of 48 percent of the likely voters polled. Three percent of likely voters are undecided.